Diagnosis of Meningitis in Children

Upon arrival at the emergency department, the child's temperature, blood pressure, respiratory rate, pulse, and oxygen in the blood may be checked. After quickly checking the child's airway, breathing, and circulation, the doctor completely examines the child to look for a focal source of infection, to assess any alteration in mental status, and to determine the presence of meningitis. If meningitis is suspected, several tests and procedures are needed to determine the diagnosis. However, early IV antibiotic treatment is often started before tests are done. In some children, the diagnosis of
fifth disease (fever, cold symptoms, followed by a rash especially on the face) or other viral infection is deemed most likely and the child will usually not need the following tests:

A spinal tap, or lumbar puncture, is an essential procedure in which cerebrospinal fluid is obtained from the child and then analyzed in a laboratory. Cerebrospinal fluid is the fluid surrounding the brain and spinal cord where the infection in meningitis occurs.

Occasionally, a CT of the brain is done before the spinal tap if other problems are suspected by the doctor (see below); most clinicians will treat the child with antibiotics before the spinal tap if bacterial-caused meningitis is strongly suspected because of the possibility of a rapid decline in condition of the patient.

To perform this simple procedure, the doctor numbs the skin on the child's lower back with a local anesthetic.

A needle is then inserted into the lower back to obtain the necessary fluid from inside the spinal cord because the fluid bathing the spinal nerves is essentially the same that bathes the brain.

The fluid is sent to a laboratory and is checked for white and red blood cells, protein, glucose (sugar), and organisms (bacteria, fungus, parasites; viruses are not visualized). The fluid is also sent for culture (cultures may take about a week for viruses).

After the needle is removed, a small bandage is placed on the skin where the needle was inserted.

A spinal tap is not a dangerous procedure for
a child. The needle is inserted at a location below the end of the
main body of the spinal cord. A spinal tap is a simple procedure
that is necessary to determine if a person has meningitis. Currently, no
other procedure is available to aid in the diagnosis of meningitis.

An IV may be started to obtain blood and to give fluids. This helps prevent dehydration and maintain a good blood pressure.

Urine may be obtained to determine if any infection is present in the child's urinary tract system.

A chest X-ray film may be taken to look for signs of infection in the child's lungs.

A CT scan is sometimes necessary if any of the following is present or suspected: